The service was great and the part was a drop in.
While a bit subjective, I combined the changing of my air filter (on a functional Ram Air 1970 Rallye 350) with a gas additive (great one, may I add). I believe between the two, clearly there was a step up in performance, especially after about 3000 RPM. I could feel the difference. I replaced a standard paper element filter with the K&N.
As this was the first time I actually purchased a new K&N filter, I did not know that they did not need to be treated with oil prior to first use. Now I know. Very convenient to be able to just drop it in.
Very positive experience, I will never go back to the previous set up. I will convert any future cars to K&N, if the replacement exists.